1. Field of the Invention
This invention relates to the field of high-protein food materials and the manufacture of such material from grain. In particular, the invention relates to a food product suitable for human consumption and substantially free of fibers, fats, and oils, the product being made from grain from which fermentable sugars have been largely extracted but having a higher protein fraction than any untreated grain, the protein fraction including effective amounts of all of the essential amino acids.
2. The Prior Art
There is currently a critical and increasing world food shortage. It is not only necessary that nations find ways to increase and to use effectively the total quantity of food available in the world but that the additional food have proper nutritional values. In particular, extra sources of protein are needed, since protein is the most important foodstuff.
The derivation of high- protein foods and food supplements from plants has been the subject of extensive investigation. Soybeans have long been known to be a good source of edible protein, and have been the subject of much study, but it is difficult to remove the basic bean taste from foods processed from soybeans, and therefore, soybean-based foods continue to be less desirable than their nutritional profile indicates that they should be. Cereal grains also contain substantial amounts of protein but generally have less nutritional value than soybeans. However, foods made from grain are not plagued by an undesirable taste.
There is a source of grain heretofore overlooked as being fit for human consumption. Substantial quantities of grain are used in the brewing industry and at the present time there is in excess of 1.5 million tons of spent grains produced each year as a by-product of the brewing industry in the United States and four times that amount world-wide. The grains are referred to as "spent" because a large percentage of fermentable sugars has been extracted from them, leaving material that is of no further value in the production of beer. This material, when dried, consists of needle-sharp particles due to the husks of the grains and, especially because of these husks, is not suitable for human consumption but is currently being sold as cattle food at a price of about one cent a pound on a dry basis. The removal of spent grains from the brewery poses potential, and sometimes actual, logistical problems, and spent grains are generally looked upon in the brewing industry as an undesirable but unavoidable waste material.
The husks of grain processed for direct human consumption as cereals, flour, etc. are not so troublesome because they are removed while the grain is still in the raw state. In that state, the husks are not bound tightly to the grain and are relatively easily removed. By the time grain has gone through the mashing process used to extract fermentable sugars in the production of beer and other alcoholic beverages, the husks have been cooked onto the grain, forming a tenacious adhesive bond between each seed and its husk. This has heretofore presented an insuperable barrier to the use of brewers spent grains as a human food material, although the digestive system of cattle permits dried spent grains to be used as cattle food, for which brewers are paid very little.
The initial process steps applied to grain in brewing beer and the like result in the production of large amounts of undesirable sewage, the removal of which is entirely an expense. Not only are brewers required to pay high sewer taxes to the communities in which breweries are located, but because of their inability to control the quantity and nature of the material they deliver to the sewage system, the brewers also have to pay high sewage surcharges.